Urothelial carcinoma (UC) arises exclusively from the urothelium including the renal pelvis,ureter, bladder and urethra, with bladder transitional cell carcinoma (TCC) being the most common form. Arsenic is a well-established human carcinogen of the skin and lung. Recent studies have well documented that the long-term exposure to inorganic arsenic through ingestion and inhalation is associated with an increased risk of bladder cancer, especially TCC.